CS274325B1 - Method of refractory concrete preparation - Google Patents

Abstract

The solution concerns a method of preparation of refractory concrete, which enables the preparation of refractory concretes with high resistance against heat and high initial and long-lasting rigidity. The refractory concrete contains a gypsum-less cement based on Portland cement clinker, ground to the specific surface area of 350 to 550 m<2>/kg in presence of liquid grinding admixture, and high temperature-resistant aggregates. Firstly 3.5 to 10 percent solution of alkaline carbonate, hydrogen carbonate or silicate is prepared and than this solution is enriched with 0.1 to 3 percent by weight of sulfonated polyphenolate and/or of lignin sulfonate with addition of 0.01 to 1 percent by weight of triethanolamine, where the amount of sulfonated polyphenolate and triethanolamine is related to the clinker weight. The principle of the solution consists in the fact that the gravel is wetted in 3 to 20 percent by weight of mixing water and then these components of the refractory concrete are mixed at the water coefficient w = 0.23 to 0.55.

Description

The invention relates to a process for preparing refractory concrete used in cast, stewed or metaed refractory materials.

Portland cement-based refractory concretes are chip materials used for special purposes. The main constituents of such concretes are, in addition to Portland cement, fillers which are characterized by sufficient heat resistance. Numerous statements are known from the literature, as described, for example, in Nekrasovl Žarostojkije's concrete on the warp of portlencement. The use of Portland cement is limited by a temperature of 1,100 to 1,200 ° C, which results in a loss of strength due to the instability of the hydrates resulting from the hydration of Portland cement. The decomposition of portlandite, which produces free calcium oxide, has a particularly negative effect. These anaesias are eliminated by the use of aluminous cements, the hydration of which does not give rise to calcium hydroxide. with high-alumina cements up to 1700 ° C. This solution, however, is very expensive. Furthermore, it is known from the literature (and No. 238 719) for refractory lining materials, in particular monolithic linings of metallurgical vessels, composed of grit based on eg magnesitchrom in a quantity of 70 to 92% by weight and from 8 to 30% cement-based binder wherein, in addition to the sanding material, the composition comprises 0.01 to 4.5% by weight of a water-soluble lignin derivative and 0.005 to 2.25% of a water-soluble alkali metal silicate or carbonate, an alkali metal or alkaline earth metal carbonate, the remainder cement clinker gypsum-free with a specific surface area of 220 to 1000 m m / kg. The refractory composition may further comprise a water-soluble sulfonated condensation product of phenols with formaldehyde in an amount of 0.005 to 2.25 weight of cement clinker.

However, there are some drawbacks to the familiar. In practice, it is necessary, in order to achieve the necessary high initial strengths, to finely grind the cementitious o

clinker, often above 600 m / kg. The workability and the initial strength required for the formation of the corresponding refractory masses are also negatively influenced by the grinding additive, in this case grinding with a pro-lignin sulphonate or grinding without any additive is considered. In particular, the start of solidification of the masses (according to No. 238 719) has a negative effect on the low concentration of alkali carbonate, where the mixture prematurely solidifies due to the reaction of the aggregate with alkali carbonate.

These disadvantages are overcome by the method of preparing the refractory concrete according to the invention. The refractory concrete comprises Portland cement clinker-free cement-free cement ground to a surface area of 350 to 550 m / kg in the presence of a liquid grinding additive, in particular a synthetic sulfonated polyelectrolyte. It further comprises high temperature resistant aggregates such as blackness, flakes, magnesite, chrommegnezlt and / or alurlt. First, a 3.5 to 10 percent solution of alkali carbonate, bicarbonate or silicate is prepared, then 8e is added to this solution from 0.1 to 3 wt. % of sulfonated polyphenoCS 274 325 B1 nolate and / or lignin sulfonate with an addition of 0.01 to 1 wt. triethanolamine, where the amount of sulfone polyphenolate and triethanolamine is based on the weight of the clinker. The essence of the invention is that the aggregate is wetted in 3 to 20% by weight. mixing components, whereupon all the refractory components are mixed at a water coefficient w »0.23 to 0.55.

By the method according to the invention, it is possible to produce refractory concretes and high heat resistance from BS cements with a specific surface area actually available on conventional grinding machines. The presence of a wettable grinding additive then allows the preparation of well workable concretes from high temperature resistant aggregates with a real onset of solidification.

The preparation method of the refractory concrete according to the invention is specified in the examples and in the table, but is not limited thereto.

Example 1

For the preparation of refractory concrete, a gypsum-free Portland cement was first prepared from the albin Prachovlce. This BS cement was ground in an 8 mill mill in the presence of 0.05% commercial Abeson TEA (sodium alkylanylbenzenesulfonone). The gypsum product was excluded during grinding. The specific surface area of this BS cement was 440 m ² / kg.

Example 2

Refractory concrete was prepared for operation of the cement kiln rotary kiln. It was blown into a box which was placed in the hot-head at the point of the burner opening into the hot-head of the rotary kiln. A mixture of BS cement (according to example 1) + aggregate resistant to temperatures up to 1,400 ° C in a ratio of 1.0 t 3.5 wt. at w 0.32.

Korten FN (sodium ferric polyphenolate with triethanol amine addition) and soda were dissolved in the mixing water. Kortan FN contained 10% TEA. The soda content corresponded to a 5% solution; the cortane content was 0.6% by weight of the cement.

During operation of the rotary kiln, a temperature of 1,140 ° C was measured at the application site of the refractory concrete according to the invention. Depending on the operation of the furnace, the refractory prepared from clay cement was observed at the same location and the refractory concrete according to the invention exhibited the same operational properties.

Example 3

For quick repair of the ceiling of the 1st clinker cooler grate, refractory concrete according to the invention was used instead of crashed shaped fireclay bricks. The space was underfloor and refractory concrete of the composition: BS cement according to example 1, aggregate resistant to temperatures up to 1000 ° C in the ratio of 1: 4 by weight was incorporated into the suspended fitting. Kortan FN and soda additives were used in the processing of refractory concrete. The soda content corresponded to a 7.5% solution.

The CS content of Corten FN was 0.8% by weight of cement. The water coefficient used was 0.34. During the operation of the cooler, the temperature at the repair location was approx. 930 ° C. During the operation of the equipment, it has proved the full success of this repair of Grinding Bricks.

Example 4

Gypsum test materials were prepared from gypsum-free cement (surface area 450 m / kg) ground in the presence of 0.05% cement grinding weight (commercial Abeson TEA). The aluminous cement masses were prepared as control tests.

Mixture No. 1 BS cement + aggregate (bricks + shale 1 with 1) in ratio 1 s 3, water with cement 0,40

Mixture No. 2 BS cement + aggregate (bricks) 1: 3, water j cement 0.40

Mix No. 3 Aluminum cement + aggregate (bricks) 1: 3, water: cement 0.60

Bricks used brick grit from aluritic bricks (AI-60), which had granulation: up to 4 mm 1.5%, up to 2 mm 12.6%, up to 1 mm 22.2 SS, up to 0.5 mm 25 , 5%. When preparing the mixture from BS cement, Kortan FN and soda were dissolved in the mixing water, the soda content in the mixing water corresponded to a 4% solution. Kortan FN content 1.1% by weight of cement.

The test results are shown in the following! table.

Table

Mix No. 1 No 2 No 3 density 2 167 2 256 2,046 kg / m deformation resistance in the heat at a load of 0.2 MPa ^τ 0,6 1 240 1 240 1400 ° C ^-t 20 1 280 1 280 1,460 ° C compressive strength after 105 ° C 67.8 87.8 42.7 MPa

additional linear changes after firing at 1200 ° C / 4 hours -1.3 -0.3 -% additional linear changes after firing at 1,400 ° C hours, - - -0.4% flexural strength after drying 4.8 5 2.7 MPa compressive strength after firing at 1200 ° C / 4 h, 49.8 31.4

- MPa

CS 274 325 Bl Mix No. 1

£. 2

5. 3 compressive strength after firing at 1400 ° C / 4 hours fire resistance

- - 20.4 MPa

350 1,350 1,530 ° C

Example 5

For the preparation of the refractory mixture, an emulsion was used: 500 kg of clinker ground on a specific surface of 470 m / kg (milk additive Abeson TEA), 200 kg of flake, 30 l of aoda solution and Kortan FN / solution contained 5.5 g aode in 1 l; 1 g Kortan FN in. In the preparation, the procedure was followed: in a mixer, a leaf of 2.5 to 5 liters (i.e. 7 to 14% of the total weight of the ground water / water) was first wetted and the mixture was rinsed. Then 30 liters of soda solution and Kortan FN were added. Cement was added after mixing. The mixture was mixed and used for the production of refractory parts for the region up to 1 180 ° C. When using 3% water to moisten the stoneware, the mixture was practically unprocessable;

Claims (1)

Process for preparing refractory concrete containing Portland cement based alumina 2 based on ground surface of 350-550 m / kg in the presence of a liquid grinding additive, in particular synthetic sulfonated polyelectrolyte, and longer containing high temperature resistant aggregates. Such as loneliness, flakes, magnesite, chromosgnezite and / or alurite, where a 3.5-10% alkali carbonate, bicarbonate or silicate solution is first prepared, then 0.1 to 3 wt. % of sulfonated polyphenolate and / or lignin sulfonate and the addition of 0.01 to 1 wt. triethanolamine, wherein the amount of sulfonated polyphenolate and trlethanolamine is related to the weight of the clinker, characterized in that the aggregate is wetted in 3 to 20 wt. All components of the refractory concrete were mixed at a water coefficient w of 0.23 to 0.55.